Assessment of patency: whitin 24 hours from end of procedure or before discharge from the hospital, a physician blinded to ACT values will assess presence of flow along the radial artery with continous Doppler probe or with color Doppler probe (patency of radial artery will be considered if antegrade flow is present during contemporary compression of ulnar artery at the wrist); if a Doppler probe is used, a confirmation of occlusion with color Doppler must be obtained (see Appendix); in case of weak/biphasic flow with Doppler, an evaluation with color Doppler must be obtained to detect a segmental stenosis. Physicians will perform Doppler and echoDoppler evaluation after adequate training. Anonymized echoDoppler images will be recorded and send to referral center where the angiologist will review the images confirming the RAO.